Welding machine



March 17, 1936 l E. J. w. RAGSDALE WELDING MACHINE original Filed Aug.2o, 1931 4 Sheets-Sheet 1r I NV EN TOR. EARL] .W RAGSDALE TTORNE yMarch17, 1936. E. J. w. 'RYAGSDAL WELDING MACHINE original Filed Aug. 2o,1951 4 sheets-sheet 2 FIGA 1A VENTOR EARLJWDAGSDALE k BY 17, 1935 E'. J.w. RAGsDALE WELDING MACHINE Original Filed A'ug. 20, 1931 4 Sheets-Sheet'3 Y M .fM%, E..

March 17, 1936. El J, w, RAGSDALE 1 2,034,536

WELDING MACHINE original Filed Aug. -2o, 1951 4 sheets-sheet 4 IHIIIIIINVENToR.

EARLlW. RAosDALE. m 401 d' BY ATTORNEY.

PmntedMu'. 17, 1936 'PATENT OFFICE WELDING moms Earl JL W'. Ragsdale.Norristown, Pa., assigner to Edward G. Budd Manufacturing Co., Philadel-.p hia, lra., a'corporation of Pennsylvania Application August 20, 1931,Serial No. 558,220

Renewed July '7, 1933 Z5 Claims.

The present invention relates to electric weld ing and more particularlyto a timing system and timing apparatus for power control forinstantaneous spot welding, especially of the kind required forstainless steel or other metals in which the degree of heat, duration ofits application, and total amount and extent of diffusion are importantfactors determining the quality of the finished product.l

In such spot welding it is necessary to apply sufficient current toraise the spot to the. weld- 'ing temperature, but very desirable inmost cases to limit the duration of current application to such briefinterval of time as will not cause a storage of heat in the surroundingmetal to an amount suiilcient to prevent proper quenching and result inimpairment of the desirable qualities of the metal. f

In practice, this brief interval `of time even when operating with 60cycle current supply, is usually less than that` required for thecurrent to reach its maximum value after closure of the circuit. Forthis reason it has been found necessary to' use a source of currentsupply of a capacity far in excess of that required, in order that therequired instantaneous current value may be attained within a timeinterval less than that required for the current source to reach itsmaximum,

, rent may be eiiected at will without danger of Because of theA excesscapacity and consequent possibility, in some cases, of overheating thework should the' current be given time to attain its.

maximum instantaneous value, it is important that the means used 'fortiming be accurate and reliable. y

1 One object of the present invention therefore isto provide a systemand apparatus for power control whereby instantaneous application andWithdrawal of the welding current may be effected with accuracy oftiming,l and whereby a single instantaneous application and terminationof currepetition or overtiming.

Heretofore in electrical welding, there has been 7 little or nonecessity Ifor extremely short period energizing impulses, and whereordinary short high speed, start-and-stop rotary switching deimpulseshave been required, either vibratory or ,vices have been' used. 7In thepresent invention,

the various diiliculties incident to the` use of ro-r tary motion suchas inability to start and stop quickly, and those incident tooscillatory or vibratory motion suchr as inertia losses, excess wear andshock, and uncertainty in timing, are overcome in general through theuse of a combination invention will be apparent from a perusal of therotary motion and reciprocating motion in a manner to take advantage ofthe uniform high speed attainable with continuous rotary'motion, and thequick intermittent movement attainable with oscillatory motion wheresuch movement is relatively small and is confined to relatively lightparts.

More specifically, some of the objects of the invention are attained bythe provision of a stationary'contact and a relatively movable contactarranged to be rotated past the stationary contact at a high rate ofspeed, and normally spaced a short distance therefrom but in4sufficiently close proximity to be readily, instantaneously moved intoand out of position to engage the stationarycontact in its passagethereover. The arrangement is such that the movable contact is i'lrstbrought into the plane or the stationary contact against an insulatingsurface in substantially the plane of the stationary contact so as tomove on to and across the stationary contact in sliding engagementtherewith, and is moved out of the plane of the stationary contact onlyafter leaving the latter at the normal high rate' of speed. The arc. ifany,`is thus broken by the relative rotary motion of the movable contactand not by the relative oscillatory movement of lthe rotary contact.Inasmuch as the oscillatory movement oi the movable contact is not acircuit breakingmovement it may be made extremely slight by makingthe'normal spacing between ther contacts suiiicient only to prevent thestriking of an arc, and striking distance, in the present instance isespecially small because of-'the fact that the air in the gap ismaintained in circulation due to the constant, relative rotary movementof the contacts.

Another important object of the invention is the provision of a pushbutton control such that the circuit making and breaking apparatus maybe readily controlled from a point remote fromthe apparatus itself andin proximity to the work, for example'by a push button adjacent ormounted onthe welding tool. I

A further object is the provision of an arrange ment for reducing thecurrent in one or more steps before each braking of the circuit.

Various other objects and advantages of the following specification andthe drawings accompanying the same.

In the drawings, which illustrate a preferred embodiment of theinvention;

Fig. 1 is av perspective view ofthe apparatus ing the timing contactsegments.

timing andcontrolling apparatus omitting thev main portion of thedriving motor.

Fig. '7 is a top plan View oi Fig. 6 omitting the mounting base for thesake of clearness.

Fig. 8 is a detail View showing the disc co'mmutator for the controlycircuit.

Fig. 9 is a rear view of the contact block show- Fig..l0 is a circuitdiagram of the complete system.

` Fig. 1l is a circuit diagram of a modified 4arrangementfforreducingan'arc, if one exists when 'breaking the circuit.

oneend of the frame carries a switch box d of standard Vtype housing asuitable switch actuated by a lever l for controlling the :nain powersupply to the welding transformer. At the top of the box d is mounted asmall snap switch Mit of standard or other suitable type controlling apower supply of relatively low voltage 'for the i control circuits.Projecting through the casing,

flater described.

below the switch box t, are a pair of welding current'terminal lugs tand t which constitute the terminals of the secondary winding of thetransformer and supply the controlled welding current to thewelding toolin a manner to be The opposite end of the 'chassis is closed by upperand lower closure panels l@ and il, and aV central transformer controlpanel l2 containing controls i3 and it for controlling the connectionsof the tap leads l5 of the transformer primary winding. Mounted in theupper panel it is a timer control panel l5 containing the timer controll l. Closure of the chassis is completed by the side closure panels itand it, and a hinged lid 20 at the top. y

Referring to the drawings in detail and particularly to Figs.'4 to 9,showing the timing and control apparatus, the supporting shelf d whichacts asa general mounting base, has secured thereto a U-shaped support2| to which is sev cured a bracket 22 which supports the verticalmounting ring 23 .integral with the bracket. .The contact block ofinsulating material such as hard insulating nbre, and the timer controlpanel l8 of bakelite or like material, are secured to the mounting ring23 by spacing studs 26 as clearly shown in perspective in Fig. 4.Ass'hown in Figs. B'and 9.' the timing contac segments. 21 mounted onthe block 24 are arranged in an arcprojectingpartly intothe circularopening in the mounting ring 22 but lspaced from the inner surface ofthe ring. A timing Y 9,084,586 assembled 'and encased, showing thecontrol brush 28 carried by a rotary vbrush arm 29 of insulatingmaterial, mountedv on the shalt $0 for rotation therewith,lis arrangedto sweeplaround over the segments 2l but normally spaced out shown inFig. 6. The brush holder ill in which thev brush is directly mounted,is' oi bifurcated form extending down each side of the brush arm 29 to apoint below the shaft (Fig. 6) WhereA it is pivotallyconnected with thevarm by means of the pivot rod 32 (Figs. 6 and 7) and is biased in a ydirection toward the contact block 24 by expansion coil springs 33 (oneshown) nested in the brush, arm and bearing against the front p ortion3d of a yoke 35 carried by the brush holder. 1 The rear extensions it ofthe yoke bear against the back of the brush arm 2Q and act as a stop tonormally hold the brush 28 spaced away from the contact segments 2l asshown in Fig. 6.

Electrical connection is made with the brush 28 by means of the atcontact.` plate 3l whichas shown in Fig. '7, isf mounted in the brushholder along side of the brush, and connects throughv a suitableflexible conductor 3d with a metallic hub sectionk 39 at the center ofthe brush arm. Electrical connection is established with this hubsection through a iloating connecting plug di! of low friction,conducting material such as hard l smooth grain carbon or graphiteresiliently held in place and permitted to move axially with the brusharm by means of a spring pressed cap-dl carried at the end of a rod d2slidably mounted in an insulating bearing d3. The cap di is springpressed against the oating plug d@ by the spring lit, normallydisplacing the brush arm 2S and shaft 3@ toward the motor lill.4 The caplll and rod l2 are of conducting material and therefore lserve to extendthe electrical connection from the plug d to the outside of theinsulating bear? ing d3 where electrical connection may be made with therod by means of lock nuts 65 threaded on to the outer end of the rod.

'I'he shaft t@ is driven by the motor dl through gear 56 and pinion i8mounted on the shaft and the motor shaft t9, respectively. The drivingshaft 30 carries, fixed thereon, a cam member 50 provided with a camgroove 5i which receives a pin 52 carried in the bend of a U-shaped yokemember 53 pivoted at 5d between the upstanding arms of the U-shapedsupport 2l., The free 'end or bend of the yoke 53 is arranged to engagethe end of the movable detent 55 through the intermediation of a wearplate 56 mohnted on the end of the yoke.- The moifable detent 55 iscarried on the end of a lever 5l pivoted at E8 and operated by anarmature 59 in turn actuated by the magnet Sli. These parts are soarranged, as is clearly shown in Fig. 7, that rotation of the shaft 3Bwill cause the yoke member 53 to oscillate toward and away fromthe"`contact block 24 due' to the action of the cam 5@ and pin 52, theshaft 2 0 being held against longitudinal movement undertensionofcompression spring M. The magnet 80, upon energization', operates to'attract the amature 58 and thereby throw the detent 55 into the v pathof the wear plate 56' to hold the yokeagainst return'movement in thedirection of the motor. The shaftv 3D, being slidably'mounted vin thesupport 2i is thereby forcedtoward the contact 7 block against thetension oi' the spring 44 due to the action of the pin 52 (now heldstationary) and thecam 5B. This forward movement oi' lof contacttherewith by a small clearance as 5 being resiliently held in rubbingcontact by the coil springs 33.v The brushis thus caused to sweep overthe contacts in engagement therewith, but only for aportion of onerevolution of the shaft due to release of the detent in that time, in amanner to be later described.

Electrical con ction is extended from each of the segments 2 to thefront side of the contact block 24 through connecting flanges 8|,individual to each segment, which connecting flanges are arranged to bebridged by a distributor brush '62 (Figs. 4 and), which latter byconnecting with one or more of such anges establisheselectricalconnection with one or more successive segments 21 to vary the effectivelength of the conducting arc formed by the segments 21. The distributingbrush 82 is carried at the end of a shaft 63 arranged to be turned bymeans of a knob 84 secured thereto outside the control panel I6, theposition of the distributor brush being indicated outside the panel bymeans of the indicator arm 85 arranged to sweep over 'indicating`buttons '88 mounted in the panel along an arc as shown in Figs. l, 3and 6. The shaft 63 is journaled in a bushing 61 which passes throughthe control panel i8 and is clamped in place by a threaded clamping ring68 which latter clamps against a bearing plate 69 placed between theclamping ring and the panel. Electrical connection is made with thedistributor brush bymeans of'the binding post 10 through a suitableflexible conductor not shown.

For controlling the magnet in synchronism with the shaft 30 a commutatordisc 1| of .insulating material is mounted at the end of the shaft 30and carries a commutator segment 12 arranged to bridge a pair ofcontacts 18, at a given point in each rotation of the shaft, thecontacts 13 being connected ,ina suitable control circuit to behereinafter described. These contacts are mounted on a block 14 ofinsulating material in turn mounted on the main support 4 by means ofthe angle piece 15.

A stop plate 16 is mounted between the support 2| and the motor side ofthe cam member 50 to engage the adjacent face of the cam member and thuslimit the movement of the shaft 30 toward the motor under the tension ofspring 44. To hold the contacting face of the brush 28 in the planeofthe segments 21 against the tension of spring 33 when moved intocontacting position'by the cam, a ramp segment 11 of insulating materialis mounted on the contact block in the arc of the contact segments asshown in Figs.- 6 and 9, the approach end of the ramp segment beingslightly beveled as indicated in Fig. 9.

I For further electrical control of the apparatus above described,aolocking relay 18 is provided which is mounted beside the apparatus asshown in Figs. 4 and 7. This relay'comprlses a mounting base 19 on whichis mounted the actuating magnet and an armature 8| therefor, pivoted at89 and arranged upon energization of. the

magnet to raise the bar 82 of insulating material.

carrying a bridging contact bar 83 normally held in engagement with apair of stationary contacts 84. ARaising of the bar. thus opens thecontacts 84. A pair of normally opencontacts 85 are mounted above thebar to be closed by the raising of the bar. A retractilespring 88connected between an anchor screw 81 and an arm 88 extending downwardlyfrom the amature pivot 89, operates to hold the armature down in thenormal position as shown in Fig. 4, and as diagrammatically shown inFig. 10. For making the several circuit connections, a binding postsupport 00 is'mounted at the opposite side of the apparatus (Fig.g3) andcarries a set of three binding posts 8|, 82 and 93.

Referring now to the circuit diagram, Fig. 10. the essential elements ofthe apparatus above described are here shown diagrammatically andindicated by similar reference numerals. In addition, the circuitdiagram shows the primary winding 94 of the welding transformer 2 withits tap terminals 95 arranged in arcsto be engaged by the Contact wiperarms 96 and 81 for varying the cators 98 and 89 arranged to sweep overtheir respectivev arcs of suitable numbered indicator buttons. Thesecondary-winding |00 terminates in the terminal lugs 8 and 9 to whichis connected the welding tool, such as the tongs |0|, by means offlexible current leads |02 and |03. Power is supplied to the primarywinding of the transformer from a suitable source of alternatingcurrent, over the power line A-B, the right hand terminal of the primarywinding being connected directly to the B-side of line while the lefthand side of the winding is arranged to be connected to the A-side ofline through the brush 28 and segments 21 of the switching mechanism.Current is supplied to the motor 41 and the various control circuitsfrom a suitable source of power over the line circuit C-D, which ispreferably of a lower voltage than that of the transformer supply, anexample of a ratio in practice being 220 volts for the transformersupply and standard 1 10 volts alternating current circuit for thecontrol circuit supply. As shown in the diagram the line conductors C-Dconnect to the binding posts 92 and 9| respectively from which theconnection lis extended directly to the motor by way of'con- The controlapparatus is completed by'a push r button |01 connected through flexibleleads |08 and |08 to the binding posts 9| and 93 respectively, theflexible leads being of suflicient length to enable the push button |01to be held and operated by the operator using the welding tongs IDI, orto be mounted on the tongs.

In operation, the control circuit switch |08 is closed, which energizesthe driving motor 41, after which the switch lever 1 (Fig. 2) of themain power switch is operated to close the switch and connect the powersupply to the power supply lines A-B (Fig. 10). mally spaced from thesegments 21, there is at this time no current flow to the transformer.The motor A4`| operating, transmits the rotation of its shaft throughthe pinion 48 and gear 48 to the The brush 28 being nordriving shaftwhich in turn rotates the brush 28 around over the segments 21 but outof con- 26 when the brushis opposite ramp segment 11 (Fig. 9) and staysin the rearward position until after the brush Ahas passed the lastcontact segment 21 moving in a counter-clockwise direction aosaiise 5 asindicated by the arrow in Fig-9. As the detent v the spring dil. .Theoperator now desiring to make a weld, adjusts the tongs it to the workand operates the push button im vto close the circuit through flexibleleadsait-it, which energizes magnet 60 over a path whichniay be tracedfrom line D, binding post 9i, iiexible conductor itt, push button lill,exible conductor lui-l,- bind- -i'ng post 93-conductor lit, bridgedcontacts M,

conductor ill, magnet et, conductor iis and binding post 92 back overline wire C.

Energization of magnet t@ causes the deterit 55 to-swing into the pathof the yoke, either immediately if the yoke is at the end of its lefthand swing', or after an extremely short interval upon the iirstsucceeding left hand swing of the yoke. It is to be noted here that thisinterval is extremely short due to the high rate of rotation of theshaft 30. As thevbrush 28 moves into a position opposite the ramp 11,the yoke tends to oscillate to the right, but meeting the detentv 55 isheld stationary, whereupon the shaft 3@ is forced tact vwith thesegments due to displacement of- 'to the left against the tension of thespring' it thus moving'th'e brush 2S into contact with the The brushcontinuing to rotate sweeps around over the cam and contact segments21m' a counter-clockwise direction, as indicated by the arrow in Fig. 9,in rubbing contact withithe segments 21, until it leaves the lastsegment, whereupon the commutator segment 12 on the disc 1i rotating.finto a position to bridge the contacts 13 closes 'the circuit ofmagnet @il of the relay 13 over a path which may be traced Vfrom lineconductor D through push button itl to binding post Q3, as beforetraced, and thence by wayof conductor H3, contacts 13," conductor ile,relay 80, conductors H5, H2 and binding post 92 baclsover line conductorC. `Elriergization of the magnet 80 operates the relay i8 to opencontacts 84 and close contacts 85.' A'I'he openingdof contacts 84 ramp"i1 under tension of the brush spring 33.-

opens the circuit of magnet 60 permitting the" brush 28. to move backaway from engaging position with the contact segments21 immediatelyafter'` leaving the last contact segment. The closure of contacts 85completes a locking circuit for the magnet 8U .which may be traced fromline conductor D through push button -i1 to bindingpost 93 as previouslytraced, and thence (l0-over conductor il@ lthrough-contacts 85, |20, 8D,

17H5, H2, 92 back over line C. The relay 18 thus remains locked Whilethe push button H01 is4 closed which holds open the circuit of magnet S0to prevent further operation of the switching mechanism until after thepush button is released. 'Ihe release of the push button opens '-thecircuit through conductors Hi8- |09 which opens theflocking circuit ofrelay 18 and restores the circuits to normal., Thus, there can be but70v one 'operation of the' switching mechanism for f each closure of thepush button, Y. although the rotary motion of the switch is.continuousi'and at high speed. As-the normal gapbetween thebrush 28 andsegments 21 need be only suiiicient to prevent' the striking of anarcthis gap can be made `21Y to breakf the circuit, the current is much-former may be traced from the A-side of line over conductor it?,binding post it, brush 26, segments 21, distributor t2, conductor iis,left hand section of primary winding sii, wiper arml s6, conductor llt,wiper arm Q1, right hand section of primary winding and back over the B-side of line.

To vary the length of the time of circuit closure the operator turns theknob ii to move the distributor brush t2 into contact 'with a varyingnumber of the connecting flanges @i to render active a greater or lessnumber oi contact segments 21 as will be clear from Fig. 4. For example,referring toFig.. 9, ifv when the last segment 21 is rendered effectiveby connection of thedistributor brush @2 with vthe correspondingconnecting ange @i of such segment only. the circuit will be closed foronennitpf timecorresponding tothe arc-covered by the segment. Adjustmentof the distributor brushto connect with 'the last two segments willaccordingly iii--A '7 Vlast two segments, and so on as `the distributorbrush is moved to connect with successive segments. i In order tofurther reduce the-electric arc between the brush 28 and contactsegments, the last two segments may be arranged4 to be ,permanently out'of operative engagement with the distributor brush and shunted byresistances as indicated inAv Fig; 11. With this arrangement, assumingthe brush 28m rotate counter-clockwise as indicated by the arrow, themovement of the brush over the segments in contact therewith will-closethe circuit through the primary winding 9S of the welding transformer,which circuit may be; traced from line wire A, conductor lill, brushZtthrough the rst segment with which .the distributor brush t2 is incontact: distriow,

tor brush 62, conductor 'i land through primary ment 21X,both're'sistances R2 vand RI are` connected V,in series between thebrush and the distributor thus reducing the current still further sothat when the brush leaves .the last segment reduced. over that of themaximum, giving a reduced arc at' breaking.

It will be noted that all during operation, regardless of -theyfrequencyof welds made, the motor runs` continuously, and continuously drives eovaccesso the rotary brush with the result that the circuit making andbreaking movement of the brush is continuous, intermittent movementbeing applied only to relatively light parts and .limited in amount tothat required to bring the brush into contact engaging position, whichamount is extremely slight due to the slight gap between the brushandthe contact segments. Even this-slight intermittent motion is derivedfrom the translation 'of a portion of the continuous rotary motion ofthe more massive moving parts such as the motor armature, gears, shaft,cam member, etc. This makes for accuracy in timing at high speeds.Accuracy and reliability are further assured through theuse oi' asubstantially constantv speed motor of ample size and capacity,

While a particular embodiment of the'invention hasbeen herein shown anddescribed for the sake of disclosure, it is to be understood that theinvention is not limited to such particular embodiment but contemplatesall such modifications and variants thereof as fairly fall withinclaims.

WhatIclaim is:

1. A timing device for electric circuits com-I prislng a pair ofrelatively movable contacts,-

meansfor continuously moving one of said contacts in relation to theVother in cyclic motion and in spaced parallel planes, enabling meansoperable upon actuation to Imove said contact,

and its plane of continuous motion into the path of the other beforecontacting therewith and out of said path after discontinuance of saidcontact ydue to said continuous relative moveinto control position toeffect an actuation of said enabling means, electrical-limiting means.

operable after each complete operation of said enabling means to rendersaidenabling means ineffective for repeated action, and electricallocking means operable to hold said limiting means in operated conditionwhile said control element is in control position and to release saidlimiting meansf upon movement of the `control element'out of controlposition.

2. A timing device for, electric welding circuits comprising a'stationary contact, a movable contact arranged to slide overthestationary contact to make and break said circuit, means forcontinuously moving said movable contact for repeated operation, biasingmeans tending to normally hold the contact out of engagement,electrically operated means operable during energization to hold saidcontacts in position for operative engagement against the tension ofsaid biasing means, a control element operable when moved'into controlposition to effect energization of the said electrically operated means,a self-locking limit relay operable upon energization to open thecircuit of said electrically operated means and close its lockingcircuit, switching means operated in the movement of said movablecontact to close the energizing circuit of said limit relay, saidholding circuit being arranged to be opened by the control element uponmovement of the control element out of control position.

3. A timing device for electric circuits comprising a stationary timingcontact connected to one terminal of a gap in the circuit, a stationarycircuit breaking contact connected to the timing contact through avoltage-reducing .resistance shunt, and a movable contact connected tothe 75 other terminal of the gap and arranged to slide rst over thetiming contact and then over the circuit breaking contact, said movablecontact" being co-axially mounted and relatively :novable as respectssaid stationary timing and circuit breaking contacts and normally biasedin a plane axially spaced therefrom, and electrical means arranged toeect an axial movement of said movable contact into the plane ofsaidstaticnary contacts, said movable contact being arranged to contactwith the circuit breaking contact before leaving the timing contact.

4. A timing device for electric circuits comprising a plurality of iixedconcentrically mounted contacts, a relatively movable contact coaxiallymounted with respect to said xed contacts, an electric motor forcontinuously coaxially moving said contacts in relation to'eachotherin`cyclic motion and in spaced parallel paths,mea.ns operable uponactuation of a control element to-movesaid movable contact into the pathof said iixed contacts before contacting therewith, and out of saidpathafter discontinnance of said contacting due to said continuous relativemovement, a control element operable when moved into control position toeiect an actuation of said means, limiting means operable after eachcomplete operation of said first named means to render said first namedmeans ineffective for repeated action during continuance of theactuation of said control element, and a locking relay operable to holdsaid limiting means in operated condition during the continuance of saidcontrol element in control position, and to 'release said limiting meansupon the release of said control element out of control position.

5. A timing device for electric circuits comprising a plurality of fixedconcentrically mounted contacts, means for pre-determining the effectivecircuit closing length of saidl contacts, a relatively movable 'contact'co-axially mounted with respect to said xed contacts, an electric motorfor continuously moving said contacts in relation to each other incyclic motion and in spaced parallel planes, means operable uponactuation of a control element to move said -movable contact into theplane of said iixed contacts before contacting therewith, and out ofsaid plane after discontinuance of said contacting due to saidcontinuous relative movement, a control element operable lwhen movedinto control position to ef-j" feet an actuation of saidlast namedmeans, lim-5" 50 iting means operable after each complete opera tion ofsaid last named means to render said last named means ineffective forrepeated action dur- A ing continuance oi' the actuation of said controlelement; and a locking relay operable to hold said limiting means inoperated condition during the continuance of said control element incontrol position, and to release said limiting means upon with respectthereto and arranged for axial movement into contacting engagementtherewith to make and break a circuit, a motor for continuously movingsaid movable contact for repeated operation relatively to said fixedcontact, biasing means tending to normally hold said contacts out ofengagement, an electrically operated enabling relay operable duringenergization to axially move said movable contact into contactingposition for operative" engagement with said xed contacts against 4thetension of Ysaid biasing means, a control element for the device, saidcontrol element when moved into operative position eiecting theenergization of said electrically operated enabling relay, a selflocking limit relay operable upon energization. to open the circuit of'said enabling relay and to vclose the lockingcircuit of itself, andrelatively movable contacts operated by the axial movement of saidmovable contact whereby to close the energizing circuit of said limitrelay after the circuit closing and opening action oi said stationaryand movable contacts, said self-locking limit relay locking circuitbeing arranged for de-energization by said control element upon themovement thereof out of control position. v

7. A timing device for an electric circuit for eecting substantiallyinstantaneous welds, in

cluding a continuouslymovable circuit closing and opening devicecomprising iixed and relatively movable coaxially mounted contactaandmeans Y. other than the contacts themselves for intermitn tentlyimparting axial movement to said movable contact for rendering the sameeective without interrupting the continuous movement oi said contacts. l4

8. A timing switch for an electric circuit comprising a continuouslymovable circuit closing and opening device including relatively movablecoaxially mounted iixed and movable contacts, a`

fixed contact, a movable contact and an electric motor arranged torotate the same, means arrangedto move said movable contact axially intoand out of contacting engagement with said xed contact withoutinterrupting said continuous' f motion, control means for said apparatusinclude ing a `control element, and means ,for rendering vsaid contactsupon actuation of said control ele ment eective for one circuit closingand open= ing action only, and thereafter to return the contact membersto their normal ineffective position.

9. A timer for electric circuits comprising a circuit and relativelymovable contacts arranged to eiect the energization' andde-energizationof -said circuit, push buttonmeans to initiate the` loperation ofthe timer, continuously rotating i of said contacts,electro-magnetic actuator means meansv for effecting the timed operationof said contacts, electro-magnetic actuator means whe operation iseiected by the' actuation of said push button means and arranged to eectthe timed engagement of said contacts, means for selecting the period ofeffective engagement of said contacts, and electrical relay meanslimiting the en-` l ergization of said circuit to'one operativeenergization only for each actuation of saidv push but- `ton means. y

10. A timing switch apparatus for electric cir- 'cuits comprisingrelatively movable contacts arranged toL effect the connection anddisconnecs tion of the circuits, push button means to initiate theoperation of the timing switch, continuously rotating means for eiectingthe timed operation whose operation is eiected by the actuation oi saidpush button means and arranged to effect the timed engagement of saidcontacts, means for selecting the period of effective engagement of saidcontacts, and means limiting the connection vof vsaid circuitsto oneoperative connection only for actuation oi button'v means, saidlastnamed means being operated by and including an electrical lockingrelay means controlled by the push button.- f

1l. A timing switch system-iorcontrolllng an aosaese i 'electric circuitcomprising relatively movable contacts arranged to eect the closing andopening oij said circuit, push button means to initiate the operation ofsaid system, continuously rotating means for effecting the timedoperation of i said contacts, electro-magnetic actuator means whoseoperation is eiected by the actuation of said push button means andarranged to effect tacts arranged to eect the energization and der yen'ergization of said circuits, push button means to initiate theoperation of said combination, continuously rotating means for effecting,the timed operation of said contacts, electro-magneticheactuation ofsaid push button means and arranged to eect the timed engagement of saidcontacts, means for selecting the period of eective engagement with saidcontacts, and means limiting the energization of said circuits to oneoperative energization only for each actuation oi said push buttonmeans, the operation of said tuator means whose operation is effected bythe last-named means being eiected by a locking.

vmeans whose operation is actuated by said actuator and terminatedbysaid push button means.

i3. A timed switch' apparatus for electric circuits comprisingrelativelymovable contacts arranged to effect the energization and cle-energie`sation of a circuit, push button means to initiate the operationof theswitch, continuousiy rotan.

ing means foreffecting the timed operationoi said contacts,electro-magnetic actuator means whose operation is effected by theactuationoi said push buttonnleans and arranged to eiect l' the timedengagement of said contacts, means for selecting the period of effectiveengagement of said contacts, means limiting the enei'gizationf of thecircuit to one operative energization only-for each actuation of saidpushbutton means, and

means arranged to open the circuit ofl said push button means whoseoperation is effected through the operation of said relatively movablecontacts.-

14,.,A timingdevice for electric circuits comprising a circuit, a pairof relatively movable corelative rotary motion between said contacts,and

Y means other than the vcontacts 'themselves for relatively axiallymoving said contacts into and vaxially mounted contacts in the circuitnormally /spacd apart, means -forv maintaining continuous 5:5`

out of. contacting relation without interrupting ,I

` said continuous relative rotary motion whereby to effect anenergization of the circuit.

15. A timing device for electric circuits comi prlslng a circuit, acontinuously mechanically operate'd rotary circuit making andV breakingmeans in said circuit including a pair of co-axlally mounted relatively`movable contacts normally occupying planes spaced apart, and means forrelatively axially moving said contacts to renderv the same electricallyoperative 'oninopera-A tive throughv their relative rotary motionwithout interrupting said continuous rotary operaftion'.

-A timing device for electric circuits lcom i prising a' circuit, acontinuously mechanically operated rotary" circuit making and' breakingv75 means comprising fixed and relatively movable co-axially mountedcontacts connected in said circuit, means normally maintaining saidcontinuously operated means ineffective to make the circuitcontrcl meansoperable to render said continuously operated means effective to makeand break the circuit through relative rotary motion between saidcontacts which means impart a relative axial movement of the contacts,and means operable after each make and break of the circuit by saidrotary motion to render said control means ineiective until it isoperated again after the completion of an initiated circuit timingoperation.

17. A timing device for electric circuits comprising a circuit, acontinuously operated relatively movable rotary'circuit closing andopening means co-axial with each other for said circuit arranged tosuccessively close and open said circuit in repeated cycles, means fornormally spacing from each other in different planes and maintaining sospaced and ineffective to close the circuit said relatively movablecircuit closing and opening means, and means for rendering the circuitclosing and opening means effective during a portion only of its rotarycycle of operation.

18. A timing device for electric circuits cornprising a fixed contactand a relatively movable co-axially mounted contact, means forcontinuously relatively moving said movable contactin rotary relation tothe other in cyclic motion and in a spaced parallel plane, enablingmeans independent of the contacts themselves for relatively axiallymoving said movable contact into the plane of the fixed contact forcontacting therewith, and means for controlling the rotary length ofsaid fixed contact which may be effective to close the circuit.

19. A timing device for electric circuits comprising a stationarycontact, a co-axially mounted movable contact arranged to slide over thestationary contact to make and break said circuit, biasing means tendingto normally hold the contacts out of engagement in spaced parallelplanes, means for continuously relatively moving said contacts in saidspaced planes and electrically operated means operable duringenergization to hold said contacts in relative positionk for operativeengagement in the plane of the stationary contact against the tension.of said biasing means.

20. A timing device for electric circuits comprising a stationarycontact, a movable contact co-axially mounted with respect to androtatable to slide over the stationary contact to make and break acircuit, means for continuously rotating the movable contact in a mannerfor repeated operation but normally in axially spaced relation to andout of contact with said stationary contact during complete revolutions,control means movable into and out of operating position, and meansoperable upon movement of the control means into operating position tomove said contacts axially into and out of contacting position once onlyand during one of the repeated opera-` tions of the movable contact. V,

21. Automatic timing mechanism for electric circuits comprisingco-axially mounted fixed and relatively rotary contact devices arrangedto lbe moved axially into initial-contacting engagement to control thesupply of current, a constant speed motor for driving said rotarycontact device, andmeans for varying at will the effective angularextent of said xed contacts while the apparatus is in operation, wherebythe period Aduring which current is supplied may be adjusted as desiredy22. In combination with an electric circuit a timing device comprisingrelatively movable contact devices arranged to effect the energizationand de-energization of the circuit, a control element for initiating theoperation of the timing device, electrical actuator means operable uponeach actuation of the control element to effect one energization andde-energization of said circuit, and a lock-out relay eiective after thecircuit energization is terminated to break the circuit of the actuatorpassing through the controlV element and the lock-out relay.

23. A timing switch apparatus to effect the connection of alternatingcurrent circuits comprising relatively movable contact devices arrangedto eiect the energization and de-energizationfof the circuits, aninitiating means for initiating an operation of the timing switch,electrical actuator means operable upon each actuation of the initiatingmeans to eiect an energization and de-energization of the circuits and alock-out relay effective to break the circuit of said electricalactuator means through the initiating means, and said lock-out relayhaving a lock-in circuit effective through the initiating means.

24. A timing system for electric welding machines comprising a highspeed continuously rotating welding circuit control switch operating tocontrol a Welding circuit through a plurality of continuously rotatingcontacts, an enabling device for cutting into and out of circuit closingand opening action said high speed continuously rotating switchingapparatus and having control of the effectiveness of said switchingapparatus, and means operating through said continuously rotatingcontacts limiting the enablement of said switching apparatus by saidenabling device to a single effective control of a welding circuitthrough its continuously rotating contacts for a single operation of theenabling device.

25. A timing system for electric circuits comprising a plurality ofrelatively movable contacts synchronously driven with respect to eachother, a circuit arranged to be energized for an adjustable denite timedperiod through said contacts, an enabling device arranged to' cut saidcontacts into and out of eifective circuit closing and opening action,means to initiate the operation oi said enabling device, and meansincluding a locking relay, jointly operating through said circuit timingcontacts and through said initiating means, whereby to limit theenabling action of said enabling device to a single effective circuitclosing operation oi said circuit contacts for each single operation ofthe initiating means. EARL J. W. RAGSDALE.

